Either make the Poor field a calc field based on the values in the Income field or set a script trigger on the Income field OnSave or OnValidate that sets the value of Poor to Yes if the value of Income < 30 . If you are using the text "30k" in Income field. You can use Abs ( Income ) < 30.

I was feeling like a fuss-bucket for mentioning it. But it was like leaving a 't' uncrossed and my OCD just couldn't leave it, LOL. I think that's your fourth typo in 40,000 posts. I DO hope you do better in future ;-)